The invention involves a method for low or even non-drift sailing of a boat having a fin keel, with a sail that is mounted outside of the center-line plane and can be brought appropriately into the wind, wherein the entire rigging, including the horizontally and vertically pivotable mast arm and the sail, can be adjusted so as to generate optimum power, and can be locked in place in this position. The invention also involves a sailing vessel comprising a ship's hull having a retractable fin keel and a hinged, pivotable mast arm, and the sail that is mounted thereon.
In the history of sailing craft, especially involving sailing, a vessel's sail carrying ability has always been functionally dependent upon its stability. The power of the sails generated via the wind--when the wind comes from a side angle rather than directly from the rear--acts not only in the vessel's driving direction, but predominantly transverse to this. This would cause the ship to capsize if structural provisions to counter this, in the form of the "stability" of the boat, were not included. There are principally two means for accomplishing this, which are commonly used in combination with one another. In order to achieve so-called stability by weights, the vessel is provided with a sort of "counterweight," the ballast. This is mounted as low as possible on the boat. Most often the ballast hangs below, on the fin keel, which is rigid and firmly mounted onto the boat. When the wind pressure tilts, or heels, the boat to one side, a distance is created between the perpendicular lines of the weight of the ballast and the counteractive hydrostatic buoyancy, which acts as a lever arm for the ballast, creating a moment that counteracts the heeling. The effectiveness of this rigid-mounted ballast can be augmented by using a movable ballast, which is positioned each time on the side facing the wind, that is, windward. Very small boats are stabilized only with movable ballast, in that the crew members sit on the windward edge of the boat and lean outward. A further means of increasing stability involves widening the vessel itself. The most obvious example of this hydrostatic stability is a raft. In this case, the empty weight of the vessel acts in conjunction with its distance from the lateral "tilting edge" of the vessel. This is the manner in which all multiple-hulled craft, such as catamarans, trimarans, and boats having lateral floating or landing outriggers, achieve the stability necessary to compensate for the heeling momentum caused by the wind.
In order for a vessel to have the greatest possible potential for speed, it must be equipped with the largest possible sails. In addition to great propulsive power, however, large sails also generate an undesired, great transverse force, which, together with the lever arm, that is, the distance between the center of pressure of the sails and the lateral center of pressure, generates great heeling momentum. Thus, up to now, generating great counteracting momentum has required much ballast and/or a very broad boat. With today's keel yachts, the ratio of the ballast to the total weight often amounts to 50% (up to 80% with regatta boats). The ballast increases the displacement of the vessels, thereby wiping out a considerable share of the advantages that it creates. It also decreases the load carrying capacity, and it requires costly measures to mount it to the ship's hull, thus making the vessels more expensive. There are also considerable disadvantages to having very wide vessels. If, for example, a boat having a high degree of hydrostatic stability capsizes, it is often difficult to correct it.
One rigging design for watercraft, known in the art from DE-OS 42 38 786.8, makes it possible for the sail or sails to be mounted outside of the center-line plane, and to be positioned such that they tilt against the wind, wherein the sail is an isosceles triangular sail that is braced with one boom at its center, and that is fastened with its base line as a fore-leach rope in a yard that can be infinitely positioned and adjusted, and is mounted over a hinged, swiveling cantilever as the mast arm. With a boat or rigging design of this type it is possible to reduce somewhat the turning moment created by the power of the wind or by the sail. With proper positioning of the sail, the line of force can be guided through the height of the rotational or rolling axis of the boat, so that the total power of the sail has only a small lever arm, or even no lever arm at all, for heeling the boat. Finally, it is even possible to guide the line of force under the centerboard or under the keel at the height of the position of the lateral center point, so that the turning moment--created by the water power and the distance of the lateral center of pressure--is compensated for by the rotational axis. The keel, which serves as the bearing surface, requires a certain setting angle to generate buoyancy in the water. In current state-of-the-art constructions, in which the fin keel is permanently mounted to the ship's hull, this setting angle is automatically set such that the boat drifts, in other words, it does not sail in the direction of its center line. Currently, this drift angle is optimally adjusted only in rare cases. In any case, it is a disadvantage that the entire hull of the boat must be designed to coincide with this angle. Because it is permanently mounted to the boat's hull, the shape of the entire hull must agree with this setting angle, causing the sailboat to sail not along its center line, but rather diagonally to this line. This generates considerable resistance, and reduces the speed of the vessel.
It is thus the object of the invention to provide a method of sailing and a sailing vessel that will enable sailing without a heeling, turning moment, and without a tilting of the vessel.